[Elecraft] K3 spurious radiation?

[John/K8AZT]

I have not been monitoring this mail list much recently so I apologize if this 
subject has been discussed previously.

I like to monitor the reversebeacon.net website while calling cq or just 
monitoring looking for a qso.  Recently I have discovered a situation which has 
me puzzled and I am hoping someone here might be able to give me some insight 
what might be happening.

When calling cq (CW) on 7.0 MHz cw,  I see several hits on the reverse beacon 
website on 7.0 MHz, however I have also seen a couple stations allegedly hearing 
me on 10.1 MHz (2 occurrences) and a station hearing me on 28 MHz bands (1 
occurrence).  I am hoping this is a problem with the skimmers, but want to check 
out if there is anything which might not be right with my K3 and/or antenna 
which might be generating unwanted radiations.  At the moment I do not have 
exact frequencies where I was being monitored.  I just thought someone might 
have a suggestion where do I proceed.

At the moment I do not have access to a frequency analyzer, but hope I can find 
one to borrow locally.

Thank you for any suggestions/comments anyone in the reflector might have.

73,
John/K8AZT
K3/ SN 1693